Development of sound source components for a new electrolarynx speech prosthesis

For many individuals who lose their voices due to laryngeal cancer or trauma, the only option for speech is to use an electrolarynx (EL), which is a battery-powered vibrator that is held to the throat. Current devices produce speech that is very machine-like in sound, with low levels of loudness and intelligibility, that also draws undesired attention to the user. A project at Draper Laboratory, the Mass. Eye and Ear Infirmary and MIT aims to develop a much improved EL called the electrolarynx communication system (ELCS), which is a DSP-based device consisting of sound source, control, and speech enhancement subsystems or modules. This paper introduces the ELCS and discusses developments to date in the sound source module. Specific topics include the design of a new linear EL transducer and investigations into glottal waveform synthesis which should result in a much more natural speech output